On Mon, 21 Jan 2019, Jakub Jelinek wrote:
> Hi!
>
> add_equal_note has special code to handle properly doubleword POPCOUNT and
> similar builtins, e.g. for POPCOUNT if we don't have DImode POPCOUNT, it can
> be expanded as 2 SImode POPCOUNTs added together, but for the REG_EQUAL note
> we want lowpart SImode SUBREG of DImode POPCOUNT.
>
> Unfortunately, this doesn't really work if the operand is constant and we
> are unlucky enough that it hasn't been folded during GIMPLE optimizations
> - we still need to use DImode POPCOUNT and take subreg of it.
>
> The following patch fixes it by padding the op0's mode to the function too
> and use it everywhere instead of GET_MODE (op0). For op1 we don't really
> need that, that is for binary operations where both arguments have the same
> mode or we don't really care about the mode of the last operand (shifts).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2019-01-21 Jakub Jelinek <ja...@redhat.com>
>
> PR target/88905
> * optabs.c (add_equal_note): Add op0_mode argument, use it instead of
> GET_MODE (op0).
> (expand_binop_directly, expand_doubleword_clz,
> expand_doubleword_popcount, expand_ctz, expand_ffs,
> expand_unop_direct, maybe_emit_unop_insn): Adjust callers.
>
> * gcc.dg/pr88905.c: New test.
>
> --- gcc/optabs.c.jj 2019-01-01 12:37:17.711965861 +0100
> +++ gcc/optabs.c 2019-01-21 13:56:18.263446049 +0100
> @@ -55,7 +55,7 @@ void debug_optab_libfuncs (void);
>
> /* Add a REG_EQUAL note to the last insn in INSNS. TARGET is being set to
> the result of operation CODE applied to OP0 (and OP1 if it is a binary
> - operation).
> + operation). OP0_MODE is OP0's mode.
>
> If the last insn does not set TARGET, don't do anything, but return 1.
>
> @@ -64,7 +64,8 @@ void debug_optab_libfuncs (void);
> try again, ensuring that TARGET is not one of the operands. */
>
> static int
> -add_equal_note (rtx_insn *insns, rtx target, enum rtx_code code, rtx op0,
> rtx op1)
> +add_equal_note (rtx_insn *insns, rtx target, enum rtx_code code, rtx op0,
> + rtx op1, machine_mode op0_mode)
> {
> rtx_insn *last_insn;
> rtx set;
> @@ -136,16 +137,16 @@ add_equal_note (rtx_insn *insns, rtx tar
> case POPCOUNT:
> case PARITY:
> case BSWAP:
> - if (GET_MODE (op0) != VOIDmode && GET_MODE (target) != GET_MODE (op0))
> + if (op0_mode != VOIDmode && GET_MODE (target) != op0_mode)
> {
> - note = gen_rtx_fmt_e (code, GET_MODE (op0), copy_rtx (op0));
> - if (GET_MODE_UNIT_SIZE (GET_MODE (op0))
> + note = gen_rtx_fmt_e (code, op0_mode, copy_rtx (op0));
> + if (GET_MODE_UNIT_SIZE (op0_mode)
> > GET_MODE_UNIT_SIZE (GET_MODE (target)))
> note = simplify_gen_unary (TRUNCATE, GET_MODE (target),
> - note, GET_MODE (op0));
> + note, op0_mode);
> else
> note = simplify_gen_unary (ZERO_EXTEND, GET_MODE (target),
> - note, GET_MODE (op0));
> + note, op0_mode);
> break;
> }
> /* FALLTHRU */
> @@ -1127,7 +1128,7 @@ expand_binop_directly (enum insn_code ic
> if (INSN_P (pat) && NEXT_INSN (pat) != NULL_RTX
> && ! add_equal_note (pat, ops[0].value,
> optab_to_code (binoptab),
> - ops[1].value, ops[2].value))
> + ops[1].value, ops[2].value, mode0))
> {
> delete_insns_since (last);
> return expand_binop (mode, binoptab, op0, op1, NULL_RTX,
> @@ -2298,7 +2299,7 @@ expand_doubleword_clz (scalar_int_mode m
> seq = get_insns ();
> end_sequence ();
>
> - add_equal_note (seq, target, CLZ, xop0, 0);
> + add_equal_note (seq, target, CLZ, xop0, NULL_RTX, mode);
> emit_insn (seq);
> return target;
>
> @@ -2340,7 +2341,7 @@ expand_doubleword_popcount (scalar_int_m
> seq = get_insns ();
> end_sequence ();
>
> - add_equal_note (seq, t, POPCOUNT, op0, 0);
> + add_equal_note (seq, t, POPCOUNT, op0, NULL_RTX, mode);
> emit_insn (seq);
> return t;
> }
> @@ -2511,7 +2512,7 @@ expand_ctz (scalar_int_mode mode, rtx op
> seq = get_insns ();
> end_sequence ();
>
> - add_equal_note (seq, temp, CTZ, op0, 0);
> + add_equal_note (seq, temp, CTZ, op0, NULL_RTX, mode);
> emit_insn (seq);
> return temp;
> }
> @@ -2589,7 +2590,7 @@ expand_ffs (scalar_int_mode mode, rtx op
> seq = get_insns ();
> end_sequence ();
>
> - add_equal_note (seq, temp, FFS, op0, 0);
> + add_equal_note (seq, temp, FFS, op0, NULL_RTX, mode);
> emit_insn (seq);
> return temp;
>
> @@ -2736,7 +2737,7 @@ expand_unop_direct (machine_mode mode, o
> if (INSN_P (pat) && NEXT_INSN (pat) != NULL_RTX
> && ! add_equal_note (pat, ops[0].value,
> optab_to_code (unoptab),
> - ops[1].value, NULL_RTX))
> + ops[1].value, NULL_RTX, mode))
> {
> delete_insns_since (last);
> return expand_unop (mode, unoptab, op0, NULL_RTX, unsignedp);
> @@ -3588,7 +3589,8 @@ maybe_emit_unop_insn (enum insn_code ico
>
> if (INSN_P (pat) && NEXT_INSN (pat) != NULL_RTX
> && code != UNKNOWN)
> - add_equal_note (pat, ops[0].value, code, ops[1].value, NULL_RTX);
> + add_equal_note (pat, ops[0].value, code, ops[1].value, NULL_RTX,
> + GET_MODE (op0));
>
> emit_insn (pat);
>
> --- gcc/testsuite/gcc.dg/pr88905.c.jj 2019-01-21 14:19:17.279746531 +0100
> +++ gcc/testsuite/gcc.dg/pr88905.c 2019-01-21 14:18:56.264091537 +0100
> @@ -0,0 +1,21 @@
> +/* PR target/88905 */
> +/* { dg-do compile } */
> +/* { dg-options "-Og -fno-tree-ccp" } */
> +/* { dg-additional-options "-mabm" { target { i?86-*-* x86_64-*-* } } } */
> +
> +int a, b, c;
> +extern void baz (int);
> +
> +static inline int
> +bar (unsigned u)
> +{
> + int i = __builtin_popcountll (-(unsigned long long) u);
> + baz (i & c);
> + return a + b + c;
> +}
> +
> +void
> +foo (void)
> +{
> + bar (2376498292ULL);
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
